Israeli Prime Minister Benjamin Netanyahu speaks on Capitol Hill in Washington, Tuesday, March 6, after being welcomed by members of the House of Representatives. During his visit to the US this week, Netanyahu spent much of it defending the Jewish state’s right to launch a preemptive strike on Iran's nuclear program.

Tel Aviv — Israeli Prime Minister Benjamin Netanyahu spent much of his visit to the US this week defending the Jewish state’s right to launch a preemptive strike on Iran's nuclear program. Such a move is necessary to block the emergence of what he says is an existential threat.

But it seems that a majority of Israelis oppose a strike without US backing, according to two public opinion surveys released after the conclusion of the White House summit with President Obama on March 5.

The polls highlight an apparent gap between official rhetoric and popular sentiment that may give Mr. Netanyahu pause: Even though Israel has an established history of unilateral attacks, it seems that there is considerable public anxiety about pursuing the same course of action in the case of Iran.

A February survey sponsored by the Israel Democracy Institute (IDI) and Tel Aviv University found that nearly two-thirds of Israeli Jews oppose a military strike without US assistance, while a poll commissioned by the liberal Haaretz newspaper during Netanyahu’s visit indicated that 58 percent opposed a unilateral attack.

The IDI poll, which sampled 600 Israelis with a 4.5 percent margin of error, found that 53 percent of Israelis believe that a lone strike on Iran would fail.

“[Israelis] are rather skeptical about the ability of Israel to have an effective independent strike on Iran,” says Tamar Hermann, a Tel Aviv University political science professor who cooperates with the Israel Democracy Institute on polling.

“They are not challenging the right to do it, it is challenging the ability to do it effectively and with international support. People don’t want Israel to become the troublemaker of the world.”

Greater support if US is on board

Israeli perceptions change, however, if the US comes on board: 65 percent of Israelis support an attack coordinated with America and 72 percent believe such a strike is likely to be effective.

A February Pew Research Center poll found that 58 percent of Americans support using force to stop Iran from gaining nuclear weapons, but Obama has urged against a hasty decision.

Even assuming the US would support military action against Iran, Israelis still lack a consensus on such a strike, Ms. Hermann notes.

Some Israelis see Iran threat as overblown

In a speech to the American Israel Public Affairs Committee, Netanyahu drew a parallel between Iran and the Nazi regime. He recounted US reluctance to attack Nazi concentration camps in 1944 because of concerns about the damage to the US war effort, implying that Israel, too, may now face the threat of genocide.

But the survey data suggests that Israelis do not believe they face an existential threat of the same nature, according to Ms. Hermann.

“These historical analogies are seen by many Israelis as overused,” she says. “The far right would buy it, but with the center and even the soft right, this rhetoric is passé.”

Indeed, according to the same poll, a 42 percent minority believe that chances are low of Iran attacking Israel if it gets a nuclear weapon.

Dahlia Scheindlin, a Tel Aviv-based independent pollster, believes that Israelis have developed a substantial degree of composure after decades of living under various types of security threats.

“Fewer and fewer people are terrified by Iran,” she says. “ Israelis in general have a high sense of resilience to existential threats. There might be an initial panic, but Israelis adjust to it.”